IPAMORELIN: Selective Growth Hormone Releasing Peptide Guide
Comprehensive guide to IPAMORELIN, the selective GHRP. Mechanism of action, research applications, dosing protocols, and comparison with other peptides.
What is IPAMORELIN?
IPAMORELIN is a synthetic pentapeptide (N-[[[3R]-2-oxoazepan-3-yl]carbonyl]-L-histidyl-D-tryptophyl-L-lysyl-L-prolinamide) that acts as a selective growth hormone secretagogue (GHS). It was developed as a more targeted alternative to earlier growth hormone releasing peptides (GHRPs) such as GHRP-2 and GHRP-6.
Classification
IPAMORELIN belongs to the GHRP class of peptides that stimulate growth hormone release through the ghrelin receptor (GHS-R1a). Unlike ghrelin itself, IPAMORELIN was designed to provide selective GH release without significant effects on other hormones.
Key Characteristics
| Property | Value |
|---|---|
| Amino acid sequence | Aib-His-D-2Nal-D-Phe-Lys-NH2 |
| Molecular weight | 711.85 g/mol |
| Peptide class | Synthetic pentapeptide |
| Receptor target | GHS-R1a (ghrelin receptor) |
| Selectivity | High GH selectivity, minimal ACTH/cortisol stimulation |
| Research status | Investigational compound |
Mechanism of Action
GHS-R1a Receptor Selectivity
IPAMORELIN exerts its effects primarily through the ghrelin receptor (GHS-R1a), a G-protein coupled receptor found in the hypothalamus and pituitary gland. When IPAMORELIN binds to GHS-R1a, it activates a signalling cascade that leads to growth hormone release from somatotroph cells.
What distinguishes IPAMORELIN from earlier GHRPs is its selectivity profile:
| Receptor/Hormone | IPAMORELIN | GHRP-2 | GHRP-6 |
|---|---|---|---|
| GHS-R1a | Strong activation | Strong activation | Strong activation |
| ACTH release | Minimal | Significant | Significant |
| Cortisol increase | Minimal | Moderate | Moderate |
| Prolactin increase | Minimal | Moderate | Moderate |
| GH pulse amplitude | Moderate | High | High |
| GH pulse frequency | Preserved | May alter | May alter |
This selectivity makes IPAMORELIN a more targeted tool for studying growth hormone physiology without the confounding effects on the hypothalamic-pituitary-adrenal axis.
Growth Hormone Release Pathway
- IPAMORELIN binds to GHS-R1a on hypothalamic neurons
- Neuropeptide Y (NPY) and growth hormone releasing hormone (GHRH) neurons are activated
- GHRH is released into the hypophyseal portal system
- GHRH stimulates somatotroph cells in the anterior pituitary
- Growth hormone is released in a pulsatile fashion
- The natural pulsatile pattern of GH release is maintained
Research Findings
Published research has demonstrated:
- Dose-dependent GH release in animal models
- Preservation of natural GH pulsatility (unlike supraphysiological doses of GHRP-2)
- Minimal effect on ACTH and cortisol levels
- No significant effect on prolactin secretion
- Potential neuroprotective effects in animal models of neurodegeneration
Research Applications
Growth Hormone Studies
IPAMORELIN is used as a research tool to:
- Study GH pulsatility and regulation
- Investigate GH feedback mechanisms
- Model GH deficiency states
- Test GH replacement strategies
Body Composition Research
Animal studies have investigated IPAMORELIN effects on:
- Lean body mass
- Fat metabolism
- Bone mineral density
- Muscle protein synthesis
Sleep Research
Growth hormone is closely linked to sleep architecture. IPAMORELIN has been studied for its effects on:
- Slow-wave sleep duration
- Sleep-related GH secretion
- Circadian rhythm patterns
Neuroprotection
Emerging research has explored potential neuroprotective effects:
- Neuronal survival in ischaemia models
- Cognitive function in ageing models
- Neuroinflammation modulation
Dosage and Administration
Important: IPAMORELIN is a research compound and is not approved for human use. The following information is for research context only.
Research Dosing Protocols
Typical research doses in published studies range from 20-80 mcg/kg body weight in animal models. Common protocols include:
| Route | Frequency | Typical Research Dose |
|---|---|---|
| Subcutaneous | Once daily (before sleep) | 20-40 mcg/kg |
| Subcutaneous | Twice daily | 10-20 mcg/kg per dose |
Administration Methods
- Subcutaneous injection: Most common route for peptide research
- Timing: Often administered in the evening to align with natural GH pulse patterns
- Reconstitution: Use bacteriostatic water for reconstitution
Timing Considerations
- Peak GH release occurs 15-30 minutes after administration
- GH half-life is approximately 15-20 minutes
- Research suggests evening dosing may better replicate natural GH pulsatility
Safety Profile
Known Effects in Research Models
Based on published research:
- Generally well-tolerated in animal studies
- No significant changes in cortisol or ACTH (advantage over GHRP-2/GHRP-6)
- No reported significant adverse effects at research doses
Contraindications (Research Context)
- Not for human consumption
- Avoid in studies involving active malignancy (GH may stimulate cell proliferation)
- May interfere with glucose metabolism (monitor blood glucose in research)
Comparison with Other Peptides
IPAMORELIN vs GHRP-2
| Parameter | IPAMORELIN | GHRP-2 |
|---|---|---|
| GH release potency | Moderate | High |
| ACTH stimulation | Minimal | Significant |
| Cortisol effect | Minimal | Moderate |
| Prolactin effect | Minimal | Moderate |
| Selectivity | High | Low |
| Research utility | Targeted GH studies | Broader GHRP studies |
IPAMORELIN vs CJC-1295
CJC-1295 (Mod GRF 1-29) is a GHRH analogue that works through a different receptor. The two can be combined in research to stimulate GH release through complementary pathways:
- IPAMORELIN: Acts on GHS-R1a (ghrelin receptor)
- CJC-1295: Acts on GHRH receptor
This combination may produce synergistic GH release in research models.
Storage and Handling
| Parameter | Recommendation |
|---|---|
| Lyophilised storage | -20C or colder |
| Reconstituted storage | 2-8C |
| Shelf life (lyophilised) | 12-24 months at -20C |
| Shelf life (reconstituted) | 1-4 weeks at 2-8C |
| Protect from | Light, moisture |
Frequently Asked Questions
Is IPAMORELIN approved for human use? No. IPAMORELIN is a research compound only. It has not been approved by any regulatory agency for human use.
What makes IPAMORELIN different from GHRP-2? IPAMORELIN is more selective for the ghrelin receptor, with minimal stimulation of ACTH, cortisol, and prolactin compared to GHRP-2.
Can IPAMORELIN be combined with CJC-1295? In research settings, the two peptides act through complementary receptors and may produce synergistic effects on growth hormone release.
For research peptides including IPAMORELIN, see our product catalogue. For storage guidelines, read our Peptide Storage Guide.